Abstract

Delivery status notifications (DSNs) are critical to the correct
operation of an email system. However, the existing Draft Standards
(RFC 3461, RFC 3462, RFC 3464) are presently limited to US-ASCII text
in the machine-readable portions of the protocol. This specification
adds a new address type for international email addresses so an
original recipient address with non-US-ASCII characters can be
correctly preserved even after downgrading. This also provides
updated content return media types for delivery status notifications
and message disposition notifications to support use of the new
address type.